Between April 2010 and March 2015, Anglian Water is investing some £70 million in providing foul water drainage so that 2,970 properties in rural communities in our region will have the option to connect to the new sewerage system. This expenditure is focussed on existing private drainage systems that have been found to be harming the environment and providing a public sewerage system has been proven to be the most cost-effective solution
In these cases we will provide a sustainable drainage system to improve the local environment and reduce the risk to public health from problems caused by the existing raw sewage discharges underground aquifers and local watercourses.
Providing a sustainable drainage system involves laying new sewers, connecting properties to the sewer, and treating the collected wastewater. The wastewater is either treated at an existing treatment works nearby or, where this is not cost-effective, by providing a new treatment works for the village.
We expect to be on-site at Woodwalton between July 2012 and February 2013.
Inevitably this work is intrusive and can cause inconvenience during the construction, but we work very hard to keep all residents informed about the planned work and progress of the work throughout the scheme. We arrange public meetings, provide leaflets and directly visit customers during the scheme to keep everyone fully informed.
The sewer system may either be a gravity sewer or a vacuum sewer. Gravity sewers allow the wastewater to flow from the properties to our treatment works via a number of pumping stations which pumps the wastewater to the next section of gravity sewer. Gravity sewers can be quite deep into the ground and sometimes soil conditions or a high water table can make it impractical to lay gravity sewers. This is typically when we lay vacuum sewers.
In a vacuum sewer the wastewater is collected in underground ‘pots’ near customers properties. A vacuum station then effectively sucks the wastewater from the pot to the pumping station where it is pumped to the works. Because gravity is not necessary, the sewers do not need to be so deep in the ground.
The collected wastewater will either be pumped to an existing treatment works nearby or a new works will be built, whichever is the most cost effective. A new treatment works may be a conventional treatment process or lagoon treatment which has a particularly low carbon emission footprint and is very efficient from an operational perspective, but it does require more land, so it is not suitable everywhere.